Tapping on this WhatsApp message is hanging the app
Recently, a message has been doing rounds on WhatsApp that is causing the app to jam for a few seconds. It contains a line saying, "If you touch the black point your WhatsApp will hang." This is followed by a black dot (and some emojis), which when tapped, does indeed hang the app momentarily. The message is being widely forwarded.
The presence of an unknown, invisible special character
The message includes symbols that WhatsApp doesn't recognize, and are thus invisible to users. When converted to HTML, the message shows the presence of "&rlm:" which is a control character. It's used to specify that a piece of text is differently aligned than the rest of it. The message contains the control character right after the black spot which when touched overwhelms WhatsApp.
Nothing malicious behind the message
Users who have had their WhatsApp crash because they followed the directions in the message out of curiosity need not worry. While you will not be able to scroll up or down for a short duration while the operations of the app are impeded, the bug in itself seems harmless. The message, only affecting Android devices, has been composed to merely vex you.